//若将一个正整数化为二进制数，在此二进制数中，
//我们将数字1的个数多于数字0的个数的这类二进制数称为A类数，否则就称其为B类数。
//实现AB类数问题求解
import java.util.Scanner;
//AB类
public class Tes4 {
    public static void main(String args[]) {
        int a, b;
        long number, result;
        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNextLong()) {
            a = 0;
            b = 0;
            number = scanner.nextLong();
            while (number != 0) {
                result = (int) (number % 2);
                if (result == 1) a++;
                if (result == 0) b++;
                number = number / 2;
            }
            System.out.println(a > b ? "a" : "b");
        }
    }
}
